License Agreements - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended			3 Months Ended		6 Months Ended
	Jun. 30, 2018	Sep. 30, 2016	Mar. 31, 2016	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
License Agreements [Line Items]
Research and development expense				$ 9,581	$ 10,265	$ 18,952	$ 18,866
Stanford License Agreements [Member] | Stanford [Member]
License Agreements [Line Items]
Payments for milestone agreement or earned royalties on achievement of milestones			$ 5,000
Payments for achievement of specified development and regulatory milestones	$ 400
Payments for milestone agreement on achievement of milestones						0
Stanford License Agreements [Member] | Stanford [Member] | Maximum
License Agreements [Line Items]
Payments for milestone agreement or earned royalties on achievement of milestones			$ 900
UCSF License And Option Agreements [Member] | Stanford [Member]
License Agreements [Line Items]
Payments for milestone agreement on achievement of milestones						0
Distributed Bio Subscription Agreement [Member]
License Agreements [Line Items]
Payments for achievement of specified development and regulatory milestones		$ 5,900
Distributed Bio Subscription Agreement [Member] | Stanford [Member]
License Agreements [Line Items]
Research and development expense				$ 100		$ 100